Cyano group-containing aromatic compounds for organic electroluminescent devices

Abstract

The present invention relates to cyano group-containing aromatic compounds that are suitable for use in electronic devices and to electronic devices, in particular organic electroluminescent devices, containing said materials.

Description

[0001] Cyano group-containing aromatics for organic electroluminescent devices

[0002] The present invention relates to cyano group-containing aromatics for use in electronic devices, in particular in organic electroluminescent devices, as well as to electronic devices, in particular organic electroluminescent devices, containing these materials.

[0003] In organic electroluminescent devices, phosphorescent organometallic complexes are often used as emitting materials. For quantum mechanical reasons, up to four times the energy and power efficiency is possible using organometallic compounds as phosphorescent emitters. In general, there is still room for improvement in electroluminescent devices, especially in electroluminescent devices that exhibit triplet emission (phosphorescence). The properties of phosphorescent electroluminescent devices are not only determined by the triplet emitters used. The other materials used, such as matrix materials, are also of particular importance. Improvements to these materials can therefore also lead to significant improvements in the properties of the electroluminescent devices.

[0004] In addition to an emission layer, many electroluminescent devices comprise additional layers, such as one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, and / or charge generation layers. These layers have a significant impact on the performance of electroluminescent devices.

[0005] Electroluminescent devices that utilize fluorescent emitters or emitters exhibiting TADF are also known. These electroluminescent devices present corresponding challenges.

[0006] Among other things, the electroluminescent devices described above are described in documents US 5,077,142, US 2010 / 0084647 A1, and US 2018 / 0170914 A1. The present compounds are not described in documents US 5,077,142, US 2010 / 0084647 A1, and US 2018 / 0170914 A1, and the compounds described in these documents relate in particular to materials that exhibit or enhance emission.

[0007] In general, there is still room for improvement in these materials, for example for use as matrix materials, particularly with regard to lifetime, but also with regard to the efficiency and operating voltage of the device.

[0008] The object of the present invention is therefore to provide compounds which are suitable for use in an organic electronic device, in particular in an organic electroluminescent device, and which, when used in this device, lead to good device properties, as well as to provide the corresponding electronic device.

[0009] In particular, the object of the present invention is to provide compounds that result in a long lifetime, good efficiency, and low operating voltage. Electron-injection materials, electron-transport materials, and hole-blocking materials contribute in particular to these properties. Furthermore, the properties of the matrix materials, also referred to herein as host materials, also have a significant influence on the lifetime and efficiency of the organic electroluminescent device.

[0010] Furthermore, it is an object of the present invention to provide compounds characterized by a low refractive index (RI). A further object of the present invention can be seen in providing compounds suitable for use in a phosphorescent or fluorescent electroluminescent device, in particular as a matrix material. In particular, it is an object of the present invention to provide matrix materials suitable for green or blue phosphorescent electroluminescent devices and optionally also for red or yellow phosphorescent electroluminescent devices.

[0011] Furthermore, the compounds should lead to devices exhibiting excellent color purity, particularly when used as host material, electron injection material, electron transport material, or hole blocking material in organic electroluminescent devices.

[0012] Another task can be seen in providing electronic devices with excellent performance as cost-effectively as possible and in consistent quality

[0013] Furthermore, the electronic devices should be able to be used or adapted for a variety of purposes. In particular, the performance of the electronic devices should be maintained over a wide temperature range.

[0014] Surprisingly, it has been found that certain compounds, described in more detail below, achieve this objective, are well suited for use in electroluminescent devices, and lead to organic electroluminescent devices that exhibit very good properties, particularly with regard to lifetime, color purity, efficiency, operating voltage, and refractive index. These compounds, as well as electronic devices, in particular organic electroluminescent devices, containing such compounds, are therefore the subject of the present invention.

[0015] The present invention relates to a compound according to formula (I), where the symbols are:

[0016] R, R a , R b , R c is, at each occurrence, the same or different: H, D, OH, F, CI, Br, I, CN, NO2, N(Ar')2, N(R 1 )2, C(=O)N(Ar')2, C(=O)N(R 1 )2, C(Ar')3, C(R 1)3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, B(Ar')2, B(R 1 )2, C(=O)Ar', C(=O)R 1 , P(=O)(Ar')2, P(=O)(R 1 )2, P(Ar')2, P(R 1 )2, S(=O)Ar', S(=O)R 1 , S(=O)2Ar', S(=O)2R 1 , OSO2Ar', OSO2R 1 , a straight-chain alkyl group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group is each substituted by one or more radicals R 1 may be substituted, wherein one or more non-adjacent CH2 groups are substituted by R 1 C=CR 1 , C=C, Si(R 1 )2, Ge(R 1 )2, C=O, C=S, C=Se, C=NR 1 , -C(=O)O-, -C(=O)NR 1 -, NR 1 , P(=O)(R 1), SO or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 1 can be substituted, two radicals R, R a , R b , R c also form a ring system with each other;

[0017] Ar' is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted, whereby two radicals Ar' which bind to the same C-atom, Si-atom, Ge-atom, N-atom, P-atom or B-atom may also be connected by a single bond or a bridge selected from B(R 1 ), C(R 1 )2, Si(R 1 )2, Ge(R 1 )2, C=O, C=NR 1 , C=C(R 1 )2, 0, S, S=O, SO2, N(R 1 ), P(R 1 ) and P(=O)R 1 , be bridged together;

[0018] R1 is, at each occurrence, the same or different: H, D, F, CI, Br, I, CN, NO2, N(Ar”)2, N(R 2 )2, C(=O)Ar”, C(=O)R 2 , P(=O)(Ar”)2, P(Ar”)2, B(Ar”)2, B(R 2 )2, C(Ar”)3, C(R 2 )3, Si(Ar”)3, Si(R 2 )3, Ge(Ar”)3, Ge(R 2 )3, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R 2 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 2 C=CR 2 -, -C=C-, Si(R 2 )2, Ge(R 2 )2, C=O, C=S, C=Se, C=NR 2 , -C(=O)O-, -C(=O)NR 2 - NR 2 , P(=O)(R 2), SO or SO2 and wherein one or more H atoms may be replaced by D, F, CI, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 2 can be substituted, two or more radicals R 1 form a ring system, whereby one or more residues R 1 form a ring system with another part of the compound;

[0019] Ar” is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is substituted by one or more radicals R 2 may be substituted, in which case two radicals Ar” which bind to the same C-atom, Si-atom, Ge-atom, N-atom, P-atom or B-atom may also be bonded by a single bond or a bridge selected from B(R 2 ), C(R 2 )2, Si(R 2 )2, Ge(R 2)2, C=O, C=NR 2 , C=C(R 2 )2, 0, S, S=O, SO2, N(R 2 ), P(R 2 ) and P(=O)R 2 , be bridged together;

[0020] R 2 is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CI, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more substituents R 2 form a ring system with each other; and i is 0, 1 or 2, preferably 0 or 1.

[0021] Preferably, in particular in compounds of formula (I), it can be provided that at least one of the radicals R a , R b , R crepresents CN, preferably at least two of the radicals R a , R b , R c for CN and particularly preferably at least three of the radicals R a , R b , R c are CN. Particularly preferably 2 to 5, very particularly preferably 3 to 5 of the radicals R a , R b , R c for CN and most preferably exactly 3 or exactly 5 of the radicals R a , R b , R c for CN.

[0022] Furthermore, in particular in compounds of formula (I), it can be provided that at least one of the radicals R a represents CN, preferably at least two of the radicals R a stand for CN.

[0023] Furthermore, in particular in compounds of formula (I), it can be provided that at least one of the radicals R b represents CN, preferably at least two of the radicals R b stand for CN.

[0024] Furthermore, in particular in compounds of formula (I), it can be provided that at least one of the radicals R c represents CN, preferably at least two of the radicals R c stand for CN.

[0025] In a further embodiment, it can be provided, in particular in compounds of formula (I), that the sum of the indices i is at most 8, preferably at most 6, particularly preferably at most 4 and particularly preferably at most 2. Furthermore, it can be provided, in particular in compounds of formula (I), that preferably at most 12, preferably at most 10, particularly preferably at most 8, particularly preferably at most 6 of the radicals R a , R b , R c are not equal to H or D.

[0026] An aryl group within the meaning of this invention contains 6 to 40 C atoms; a heteroaryl group within the meaning of this invention contains 3 to 40 C atoms and at least one heteroatom, with the proviso that the sum of C atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. An aryl group or heteroaryl group is understood to be either a simple aromatic cycle, i.e. benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine, thiophene, etc., or a condensed (fused) aryl or heteroaryl group, for example naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. Aromatics linked to one another by a single bond, such as biphenyl, are not referred to as aryl or heteroaryl groups, but as an aromatic ring system.

[0027] An aromatic ring system within the meaning of this invention contains 6 to 60 C atoms in the ring system. A heteroaromatic ring system within the meaning of this invention contains 3 to 60 C atoms and at least one heteroatom in the ring system, with the proviso that the sum of C atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O, and / or S. An aromatic or heteroaromatic ring system within the meaning of this invention is understood to mean a system that does not necessarily contain only aryl or heteroaryl groups, but in which several aryl or heteroaryl groups can also be linked by a non-aromatic unit, such as a C, N, or O atom. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene, etc.are understood as aromatic ring systems within the meaning of this invention, as are systems in which two or more aryl groups are linked, for example, by a short alkyl group. The aromatic ring system is preferably selected from fluorene, 9,9'-spirobifluorene, 9,9-diarylamine, or groups in which two or more aryl and / or heteroaryl groups are linked by single bonds.

[0028] In the context of the present invention, an aliphatic hydrocarbon radical or an alkyl group or an alkenyl or alkynyl group which may contain 1 to 20 C atoms and in which individual H atoms or CH2 groups may be substituted by the above-mentioned groups, preferably the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neo-pentyl, cyclopentyl, n-hexyl, neo-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, Cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentinyl, hexynyl, heptynyl or octynyl.In general, alkyl groups according to the present invention may be straight-chain, branched, or cyclic, wherein one or more non-adjacent CH2 groups may be replaced by the above-mentioned groups; furthermore, one or more H atoms may be replaced by D, F, Cl, Br, I, CN, or NO2, preferably D, F, Cl, or CN, more preferably D or F, particularly preferably D.

[0029] An aromatic or heteroaromatic ring system with 5 - 60 or 5 to 40 aromatic ring atoms, which may also be substituted with the above-mentioned radicals and which may be linked to the aromatic or heteroaromatic ring via any position, is understood to mean, in particular, groups derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, triphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, Dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline,Phenothiazin, Phenoxazin, Pyrazol, Indazol, Imidazol, Benzimidazol, Naphthimidazol, Phenanthrimidazol, Pyridimidazol, Pyrazin- imidazol, Chinoxalinimidazol, Oxazol, Benzoxazol, Naphthoxazol, Anthroxazol, Phenanthroxazol, Isoxazol, 1 ,2-Thiazol, 1 ,3-Thiazol, Benzo- thiazol, Pyridazin, Hexaazatriphenylen, Benzopyridazin, Pyrimidin, Benzpyrimidin, Chinoxalin, 1 ,5-Diazaanthracen, 2,7-Diazapyren, 2,3-Diaza- pyren, 1 ,6-Diazapyren, 1 ,8-Diazapyren, 4,5-Diazapyren, 4,5,9, 10-Tetra- azaperylen, Pyrazin, Phenazin, Phenoxazin, Phenothiazin, Fluorubin, Naphthyridin, Azacarbazol, Benzocarbolin, Phenanthrolin, 1 ,2,3-Triazol, 1 ,2,4-Triazol, Benzotriazol, 1 ,2,3-Oxadiazol, 1 ,2,4-Oxadiazol, 1 ,2,5-Oxa- diazol, 1 ,3,4-Oxadiazol, 1 ,2,3-Thiadiazol, 1 ,2,4-Thiadiazol, 1 ,2,5-Thiadi- azol, 1 ,3,4-Thiadiazol, 1 ,3,5-Triazin, 1 ,2,4-Triazin, 1 ,2,3-Triazin, Tetrazol, 1 ,2,4,5-Tetrazin, 1 ,2,3,4-Tetrazin, 1 ,2,3,5-Tetrazin, Purin, Pteridin, Indolizin und Benzothiadiazol oder Gruppen,which are derived from combinations of these systems.,

[0030] For the purposes of this description, the phrase "two or more residues can form a ring" is understood to mean, among other things, that the two residues are linked by a chemical bond with the formal elimination of two hydrogen atoms. This is illustrated by the following scheme.

[0031] In education

[0032] Furthermore, the above formulation should also be understood to mean that if one of the two residues represents hydrogen, the second residue binds to the position to which the hydrogen atom was bonded, forming a ring. This is illustrated by the following scheme: Particularly preferred are compounds according to one of the formulas (II

[0033] Formula (II-5) Formula (II-6)

[0034] Formula (11-11) Formula (11-12)

[0035]

[0036] Formula (II-23) Formula (II-24) where the symbols i, R, R a , R b and R c have the meanings given above, in particular for formula (I).

[0037] Compounds of the formulas (II-1), (II-3), (II-8) to (II-13), (11-17), (11-18), (11-19), (11-21) to (II-24) and (II-26) are preferred and compounds of the formulas (II-8) to (11-13), (11-17), (11-18), (11-19), (11-21) and (II-26) are particularly preferred.

[0038] Preferably, in particular in compounds of formulas (II-1) to (II-26), it can be provided that at most one of the radicals R a , R b , R c is CN, preferably none of the radicals R a , R b , R c stands for CN.

[0039] The sum of the indices i in compounds of the formulas (II-1) to (II-26) is preferably at most 8, more preferably at most 6, particularly preferably at most 4 and particularly preferably at most 2.

[0040] Furthermore, in particular in compounds of the formulas (II-1) to (II-26) it can be provided that at most 10, preferably at most 6, particularly preferably at most 4 of the radicals R a , R b , R c are not equal to H or D. Furthermore, for example, in compounds of the formulas (I) and (II-1) to (II-26) it can be provided that at most one of the radicals R stands for CN, preferably none of the radicals R stands for CN.

[0041] Preferably, for example, in compounds of formulas (I) and (II-1) to (II-26) it can be provided that at most two, preferably at most one of the radicals R, R a , R b , R c in a phenyl ring represents CN.

[0042] Particularly preferably, for example, in compounds of formulas (I) and (II-1) to (II-26), the compound may not have structures in which a phenyl ring has more than two, preferably more than one, CN group. The preferences outlined above relate to phenyl rings, which may be part of a fused aromatic ring. Accordingly, these statements apply accordingly to fused aryl or heteroaryl groups, which preferably have at most two, particularly preferably at most one, CN group.

[0043] A CN group refers to a cyano group unless explicitly stated otherwise.

[0044] Furthermore, it can be provided that at least one phenyl ring has no proton in the ortho position to a cyano group (CN group). If the compound has more than one CN group bonded to phenyl rings, preferably at least 50% of the cyano groups (CN groups) have no proton in the ortho position, with particular preference for no proton in the ortho position to a cyano group bonded to a phenyl ring.

[0045] Among the particular advantages that can be achieved by this embodiment is, in particular, a longer service life of the electronic devices.

[0046] Preferably, it can be provided that in a phenyl ring in the ortho position to a cyano group (CN group) there is a substituent selected from D, a straight-chain alkyl group having 1 to 20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group is substituted by one or more radicals R1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R 1 may be substituted. In the event that the compound has more than one CN group bonded to phenyl rings, preferably at least 50% of the cyano groups (CN groups) have a substituent in the ortho position, with particular preference being given to a substituent in each case in the ortho position to a cyano group bonded to a phenyl ring, the substituent being selected from D, a straight-chain alkyl group having 1 to 20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group is substituted by one or more radicals R 1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R 1may be substituted. The preferences outlined above apply to phenyl rings, which may be part of a fused aromatic ring. Accordingly, these statements apply to fused aryl or heteroaryl groups, which preferably have a maximum of two, particularly preferably a maximum of one, CN group.

[0047] In one embodiment, it can be provided that the compound does not contain a carbazole group, preferably a carbazole group and / or no substituents of the formula N(Ar')2, N(R 1 )2 and particularly preferably does not comprise a hole transport group.

[0048] Compounds that do not comprise a hole transport group are particularly suitable as electron injection material, electron transport material or hole blocking material that are used in a corresponding layer, whereby this layer generally does not contain an emitting compound.

[0049] In a further embodiment, it can be provided that the compound comprises at least one hole transport group, preferably a carbazole group and / or a substituent of the formula N(Ar')2, and particularly preferably a carbazole group.

[0050] Compounds comprising at least one hole transport group are particularly suitable as host materials used in combination with an emitting compound.

[0051] Hole-transport groups are widely known in the scientific community. These include, in particular, di- and triarylamine groups, carbazole groups, and groups with similar properties.

[0052] In a preferred embodiment, it can be provided that the radical R, R a , R c does not comprise an aromatic or heteroaromatic ring system which has three linearly condensed aromatic 6 rings, wherein preferably none of the radicals R, R a , R can aromatic or heteroaromatic ring system having three linearly condensed aromatic 6-membered rings.

[0053] Most preferably, the compound may not comprise an aromatic or heteroaromatic ring system having three aromatic 6 rings fused to one another.

[0054] In a preferred development of the present invention, it can be provided that at least two, preferably adjacent radicals R, R a , R b , R c with the other groups to which the two residues R, R a , R b , R c bind, forming a condensed ring, where the two residues R, R a , R b , R c form at least one structure of the formulas (RA-1) to (RA-12)

[0055] Formula RA-1 Formula RA-2 Formula RA-3

[0056] Formula RA-10 Formula RA-11 Formula RA-12 where R 1has the meaning explained above, the dashed bonds are the attachment points to the atoms of the groups to which the two radicals R, R a , R b , R c bind, represent, and the other symbols have the following meaning:

[0057] Y 1 is the same or different at each occurrence C(R 1 )2, (R 1 )2C-C(R 1 )2, (R 1 )C=C(R 1 ), NR 1 , NAr', 0 or S, preferably C(R 1 )2, (R 1 )2C-C(R 1 )2, (R 1 )C=C(R 1 ), 0 or S;

[0058] R d is, identically or differently at each occurrence, F, a straight-chain alkyl group having 1 to 40 C atoms or an alkenyl group having 2 to 40 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl or alkynyl group is in each case substituted with one or more radicals R 2may be substituted, wherein one or more non-adjacent CH2 groups are substituted by R 2 C=CR 2 , C=C, Si(R 2 )2, C=O, C=S, C=Se, C=NR 2 , -C(=O)O-, -C(=O)NR 2 -, NR 2 , P(=O)(R 2 ), SO or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 2 can be substituted; two radicals R d also with each other or a residue R d with a remainder R 1 or form a ring system with another group, where R 2has the meaning given in claim 1; r is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, particularly preferably 0 or 1; s is 0, 1, 2, 3, 4, 5 or 6, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2; t is 0, 1, 2, 3, 4, 5, 6, 7 or 8, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2; v is 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2.

[0059] Structures of the formulas RA-1, RA-3, RA-4 and RA-5 are preferred and structures of the formulas RA-4 and RA-5 are particularly preferred.

[0060] In a preferred embodiment of the invention, preferably at least two, preferably adjacent, radicals R, R a , R b , R c with the other groups to which the two residues R, R a , R b , R c bind, a condensed ring, where the two residues R, R a , R b , R cForm structures of formulas (RA-1 a) to (RA-4f) where the dashed bonds represent the attachment points to the atoms of the groups to which the two residues R, R a , R b , R c bind, the index m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2 and the symbols R 1 , R 2 , R d and the indices s and t have the meaning set out above, in particular for formula (I) and / or formulas (RA-1) to (RA-12).

[0061] Structures of the formula RA-4f are preferred.

[0062] Furthermore, it can be provided that the at least two radicals R, R a , R b , R c , which form structures of the formulas (RA-1 ) to (RA-12) and / or (RA-1 a) to (RA-4f) and form a condensed ring, radicals R, R a , R b , R cwhich each bind to adjacent C atoms, whereby these C atoms are preferably connected via a bond.

[0063] In a further preferred embodiment, preferably at least two, preferably adjacent, radicals R, R a , R b , R c with the other groups to which the two residues R, R a , R b , R c bind, a condensed ring, where the two residues R, R a , R b , R c Form structures of the formula (RB) where R 1 has the meaning given above, in particular for formula (I), the dashed bonds represent the attachment points via which the two radicals R, R a , R b , R c bind, the index m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and Y 2 C(R 1 )2, NR 1 , NAr', BR 1 , BAr', 0 or S, preferably C(R 1)2, NAr' or 0, particularly preferably C(R 1 )2 or 0, where Ar' has the meaning given above, in particular for formula (I).

[0064] Furthermore, it can be provided that the at least two radicals R, R a , R b , R c , which form structures of the formula (RB) and form a condensed ring, residues R, R a , R b , R c which each bond to adjacent C atoms, wherein these C atoms are preferably connected via a bond. In particular, it can be provided that in preferred structures / compounds, the sum of the indices r, s, t, v, m, and n is preferably 0, 1, 2, or 3, particularly preferably 1 or 2.

[0065] Particularly preferably, the compounds are selected from compounds of the formulas (III-1) to (III-6), wherein the compounds have at least one condensed ring,

[0066] Formula (III-3) Formula (III-4) where the symbols R, R a , R b and R c have the meanings given above, in particular for formula (I), the symbol o represents the condensation sites of the at least one condensed ring and the following applies to the further indices used: k is at each occurrence independently 0 or 1; and i is at each occurrence independently 0, 1 or 2, preferably 0 or

[0067] 1.

[0068] The sum of the indices k and i in formulas (III-1) to (III-6) is preferably at most 8, more preferably at most 6, particularly preferably at most 4 and particularly preferably at most 2.

[0069] Furthermore, in particular for compounds of the formulas (III-1) to (III-6), it can be provided that the condensed ring is formed by structures of the formulas (RA-1) to (RA-12), (RA-1 a) to (RA-4f) and / or (RB), as previously shown, preferably by structures of the formulas (RA-1) to (RA-12) and / or (RA-1 a) to (RA-4f).

[0070] Preferably, the compounds may comprise at least two condensed rings, wherein at least one condensed ring is formed by structures of the formulas (RA-1) to (RA-12) and / or (RA-1a) to (RA-4f) and a further ring is formed by structures of the formulas (RA-1) to (RA-12), (RA-1a) to (RA-4f) or (RB). Furthermore, the substituents R, R a , R b , R c and R 1 according to the above formulas with the ring atoms of the ring system to which the substituents R, R a , R b , R c and R 1bind, do not form a fused aromatic or heteroaromatic ring system. This excludes the formation of a fused aromatic or heteroaromatic ring system with possible substituents R 1 and R 2 which are bound to the substituents R, R a , R b , R c and R 1 may be bound.

[0071] When the compound according to the invention is substituted with aromatic or heteroaromatic groups R, R a , R b , R c , R 1 or R 2is substituted, it is preferred if these do not contain any aryl or heteroaryl groups with more than two directly fused aromatic six-membered rings. Particularly preferably, the substituents do not contain any aryl or heteroaryl groups with directly fused six-membered rings. This preference is due to the low triplet energy of such structures. Condensed aryl groups with more than two directly fused aromatic six-membered rings that are nevertheless also suitable according to the invention are phenanthrene and triphenylene, since these also have a high triplet level.

[0072] Furthermore, it can be provided that the remainder R, R a , R b , R c , R 1 or R 2does not comprise an aromatic or heteroaromatic ring system having three linearly condensed aromatic 6-rings, wherein preferably none of the radicals R comprises an aromatic or heteroaromatic ring system having three linearly condensed aromatic 6-rings.

[0073] Furthermore, it can be provided that the substituents R, R a , R b , R c , R 1 according to the above formulas, do not form a condensed aromatic or heteroaromatic ring system with the ring atoms of the ring system, preferably not a condensed ring system. This excludes the formation of a condensed ring system with possible substituents R 1 and R 2 which are bound to the residues R, R a , R b , R c , R 1 may be bound.

[0074] When two residues, which can be selected in particular from R, R a , R b , R c , R 1 and / or R2 , together form a ring system, this can be mono- or polycyclic, aliphatic, heteroaliphatic, aromatic or heteroaromatic. The radicals forming a ring system can be adjacent, ie these radicals are bonded to the same carbon atom or to carbon atoms that are directly bonded to each other, or they can be further apart. Furthermore, the radicals bonded to the substituents R, R a , R b , R c , R 1 and / or R 2 provided ring systems can also be connected to each other via a bond, so that a ring closure can be achieved.

[0075] Furthermore, it can be provided that at least one radical R, R a , R b , R cis selected at each occurrence, identically or differently, from the groups of the following formulas Ar-1 to Ar-76 and / or the group Ar' is selected at each occurrence, identically or differently, from the groups of the following formulas Ar-1 to Ar-76,

[0076] Ar-59 Ar-60 Ar-61 Ar-62

[0077] Ar-76 where R 1 has the meanings given above, the dashed bond represents the bond to the corresponding group and furthermore:

[0078] Ar 1 is at each occurrence, identically or differently, a bivalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, each of which is substituted by one or more radicals R 1 can be substituted;

[0079] A is the same or different at each occurrence C(R 1 )2, NR 1, 0 or S; p is 0 or 1 , where p = 0 means that the group Ar 1 is not present and that the corresponding aromatic or heteroaromatic group is directly bonded to the corresponding residue; q is 0 or 1 , where q = 0 means that no group A is bonded to this position and that the corresponding carbon atoms are bonded instead to residues R 1 are bound.

[0080] Structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-40), (Ar-41), (Ar-42), (Ar-43), (Ar-44), (Ar-45), (Ar-46), (Ar-69), (Ar-70), (Ar-75), (Ar-76) are preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-76) are particularly preferred.

[0081] If the above-mentioned groups for structures of the formulas (Ar-1) to (Ar-76) have several groups A, all combinations from the definition of A are possible. Preferred embodiments are then those in which a group A represents NR 1 and the other group A for C(R 1 )2 or in which both groups A for NR 1 or in which both groups A stand for 0.

[0082] If A for NR 1 the substituent R 1 which is bonded to the nitrogen atom, preferably represents an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which can also be substituted by one or more radicals R 2 In a particularly preferred embodiment, this substituent R 1identically or differently on each occurrence, represents an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, in particular having 6 to 18 aromatic ring atoms, which does not contain any condensed aryl groups and which does not contain any condensed heteroaryl groups in which two or more aromatic or heteroaromatic 6-ring groups are directly fused to one another, and which in each case is also substituted by one or more radicals R 2 may be substituted. Phenyl, biphenyl, terphenyl and quaterphenyl are preferred. Triazine, pyrimidine and quinazoline are also preferred, as listed above for Ar-47 to Ar-50, Ar-57 and Ar-58, where these structures are substituted by R 1 by one or more residues R 2 can be substituted.

[0083] If A for C(R 1 )2, the substituents R 1which are bonded to this carbon atom, preferably identically or differently on each occurrence, represent a linear alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which can also be substituted by one or more radicals R 2 R is particularly preferably 1 represents a methyl group or a phenyl group. The radicals R 1 also form a ring system with each other, which leads to a spiro system.

[0084] In the following, preferred substituents R, R a , R b , R c and R d described.

[0085] Preferably, it can be provided that for the symbols used, for example, in formulas (I), (II-1) to (II-26), (III-1) to (III-6), etc., the following applies:

[0086] R a , Rb , R c is the same or different at each occurrence: H, D, CN, N(Ar')2, N(R 1 )2, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, wherein one or more non-adjacent CH2 groups are substituted by R 1 C=CR 1 , C=C or Si(R 1 )2, or an aromatic or heteroaromatic ring system with 5 to 30 aromatic ring atoms, each of which is substituted by one or more radicals R 1 may be substituted; two radicals R may also be substituted with each other or a radical R may be substituted with another group, in particular a radical R c form a ring system.

[0087] Preferably, it can be provided that for the symbols used, for example, in formulas (I), (II-1) to (II-26), (III-1) to (III-6) etc., the following applies:

[0088] R is the same or different at each occurrence and is H, D, N(Ar')2, N(R 1 )2, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )s, B(Ar')2, B(R 1 )2, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, wherein one or more non-adjacent CH2 groups are substituted by R 1 C=CR 1 , C=C or Si(R 1 )2, or an aromatic or heteroaromatic ring system with 5 to 30 aromatic ring atoms, each of which is substituted by one or more radicals R 1may be substituted; two radicals R may also be substituted with each other or a radical R may be substituted with another group, in particular a radical R c form a ring system.

[0089] In a preferred embodiment of the invention, the radical R is the same or different on each occurrence and is selected from the group consisting of H, D, F, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R 1 can be substituted.

[0090] In a further preferred embodiment of the invention, the radical R a , R b , R cidentically or differently on each occurrence selected from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R 1 can be substituted.

[0091] Furthermore, it can be provided that at least one radical R, R a , R b , R c is selected, identically or differently at each occurrence, from the group consisting of H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which is reacted with one or more radicals R 1may be substituted, or a group N(Ar')2, particularly preferably at least one substituent R, R a , R b , R c is selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted, or a group N(Ar')2. Especially preferred is at least one substituent R, R a , R b , R c is selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted. In a further preferred embodiment of the invention, the substituents R, R a , R b , R ceither a ring according to the structures of the formulas (RA-1 ) to (RA-12), (RA-1 a) to (RA-4f) or (RB) or the radical R, R a , R b , R c is selected, identically or differently at each occurrence, from the group consisting of H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which is reacted with one or more radicals R 1 may be substituted, or a group N(Ar')2. Particularly preferred is the radical R, R a , R b , R c identically or differently on each occurrence selected from the group consisting of H, D or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 18 aromatic ring atoms, particularly preferably having 6 to 13 aromatic ring atoms, each of which is substituted with one or more radicals R 1 can be substituted.

[0092] Furthermore, it can be provided that at least one radical R, Ra , R b , R c represents an aromatic or heteroaromatic ring system with 5 to 13 aromatic ring atoms, which is substituted by one or more radicals R 1 can be substituted.

[0093] Preferably, it can be provided that at least one radical, preferably a substituent R, R a , R b , R c is selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, each of which is substituted with one or more radicals R 1 may be substituted. The term substituent means in particular that R, R a , R b , R c are not equal to H. Furthermore, the substituents R, R a , R b , Rc be the same or different if two or more substituents are present which are selected from the aromatic or heteroaromatic group mentioned.

[0094] In a preferred embodiment of the invention, R d identically or differently on each occurrence selected from the group consisting of a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R 2 can be substituted.

[0095] In a further preferred embodiment of the invention, R didentically or differently on each occurrence selected from the group consisting of a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2 may be substituted, an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, which is substituted with one or more radicals R 2 may be substituted. R is particularly preferably d identically or differently on each occurrence selected from the group consisting of a straight-chain alkyl group having 1 to 5 C atoms or a branched or cyclic alkyl group having 3 to 5 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2may be substituted or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 18 aromatic ring atoms, particularly preferably having 6 to 13 aromatic ring atoms, each of which is substituted by one or more radicals R 2 can be substituted.

[0096] In a preferred embodiment of the invention, R d at each occurrence, identically or differently selected from the group consisting of a straight-chain alkyl group having 1 to 6 C atoms or a cyclic alkyl group having 3 to 6 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2 may be substituted, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, each substituted by one or more radicals R 2 can be substituted; two radicals R d also form a ring system with each other. R is particularly preferably dat each occurrence, identically or differently selected from the group consisting of a straight-chain alkyl group having 1, 2, 3 or 4 C atoms or a branched or cyclic alkyl group having 3 to 6 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2 may be substituted, but is preferably unsubstituted, or an aromatic ring system having 6 to 12 aromatic ring atoms, in particular having 6 aromatic ring atoms, each substituted by one or more, preferably non-aromatic, radicals R 2 may be substituted, but is preferably unsubstituted; two radicals R d form a ring system with each other. R is particularly preferably d at each occurrence, identically or differently selected from the group consisting of a straight-chain alkyl group having 1, 2, 3 or 4 C atoms, or a branched alkyl group having 3 to 6 C atoms. R is most preferably dfor a methyl group or for a phenyl group, where two phenyl groups together can form a ring system, with a methyl group being preferred over a phenyl group.

[0097] Preferred aromatic or heteroaromatic ring systems for which the substituents R, R a , R b , R c , R dor Ar' or Ar" are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, which may be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which may be linked via the 1-, 2-, 3- or 4-position, naphthalene, in particular 1- or linked naphthalene, indole, benzofuran, benzothiophene, carbazole, which may be linked via the 1-, 2-, 3- or 4-position, dibenzofuran, which may be linked via the 1-, 2-, 3- or 4-position, dibenzothiophene, which may be linked via the 1-, 2-, 3- or 4-position, indenocarbazole, Indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, anthracene, pyrene, perylene, chrysene, phenanthrene or triphenylene,which are each substituted with one or more radicals R, 1 or R 2 may be substituted. The structures (Ar-1) to (Ar-76) listed above are particularly preferred, with structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-40), (Ar-41), (Ar-42), (Ar-43), (Ar-44), (Ar-45), (Ar-46), (Ar-69), (Ar-70), (Ar-75), (Ar-76) being preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-76) being particularly preferred. With regard to the structures (Ar-1) to (Ar-76), it should be noted that these can be substituted with a substituent R 1 are shown. In case R d and Ar" these substituents R 1 by R 2 to replace.

[0098] Other suitable groups R, R a , R b , R c are groups of the formula -Ar 4 -N(Ar 2 )(Ar 3 ), where Ar 2 , Ar 3 and Ar4 identically or differently on each occurrence represent an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, each of which is substituted by one or more radicals R 1 The total number of aromatic ring atoms of Ar 2 , Ar 3 and Ar 4 maximum 60 and preferably maximum 40. Ar 4 and Ar 2 with each other and / or Ar 2 and Ar 3 with each other also by a group selected from C(R 1 )2, NR 1 , 0 or S. Preferably, the connection of Ar 4 and Ar 2 with each other or from Ar 2 and Ar 3 are ortho to the position of the linkage to the nitrogen atom. In a further embodiment of the invention, none of the groups Ar 2 , Ar 3 or Ar 4 connected to each other.

[0099] Ar is preferred4 an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 12 aromatic ring atoms, each of which is substituted by one or more radicals R 1 may be substituted. Particularly preferred is Ar 4 selected from the group consisting of ortho-, meta- or para-phenylene or ortho-, meta- or para-biphenyl, each of which is substituted by one or more radicals R 1 may be substituted, but are preferably unsubstituted. Ar is particularly preferred 4 an unsubstituted phenylene group.

[0100] Preference is given to Ar 2 and Ar 3 identically or differently on each occurrence, an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, each substituted by one or more radicals R 1 Particularly preferred groups Ar 2 or Ar 3are, identically or differently at each occurrence, selected from the group consisting of benzene, ortho-, meta- or para-biphenyl, ortho-, meta-, para- or branched terphenyl, ortho-, meta-, para- or branched quaterphenyl, 1-, 2-, 3- or 4-fluorenyl, 1-, 2-, 3- or 4-spiro-bifluorenyl, 1- or 2-naphthyl, indole, benzofuran, benzothiophene, 1-, 2-

[0101] 3- or 4-carbazole, 1-, 2-, 3- or 4-dibenzofuran, 1-, 2-, 3- or 4-di-benzothiophene, indenocarbazole, indolocarbazole, 2-, 3- or 4-pyridine, 2-,

[0102] 4- or 5-pyrimidine, pyrazine, pyridazine, triazine, phenanthrene or triphenylene, each of which is substituted by one or more radicals R 1 may be substituted. Particularly preferred are Ar 2 and Ar 3identically or differently on each occurrence selected from the group consisting of benzene, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, in particular 1-, 2-, 3- or 4-fluorene, spirobifluorene, in particular 1-, 2-, 3- or 4-spirobifluorene or dibenzofuran, in particular 1-, 2-, 3- or 4-dibenzofuran.

[0103] In a further preferred embodiment of the invention, R 1 identically or differently on each occurrence selected from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2may be substituted, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, each substituted by one or more radicals R 2 may be substituted. In a particularly preferred embodiment of the invention, R 1 identically or differently on each occurrence selected from the group consisting of H, a straight-chain alkyl group having 1 to 6 C atoms, in particular having 1, 2, 3 or 4 C atoms, or a branched or cyclic alkyl group having 3 to 6 C atoms, where the alkyl group is substituted with one or more radicals R 2 may be substituted, but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, each substituted by one or more radicals R 5 can be substituted, but is preferably unsubstituted.

[0104] In a further preferred embodiment of the invention, R 2identical or different on each occurrence H, an alkyl group having 1 to 4 C atoms or an aryl group having 6 to 10 C atoms, which may be substituted by an alkyl group having 1 to 4 C atoms, but is preferably unsubstituted.

[0105] In compounds according to the invention that are processed by vacuum evaporation, the alkyl groups preferably have no more than five C atoms, more preferably no more than 4 C atoms, and most preferably no more than 1 C atom. For compounds that are processed from solution, compounds that are substituted by alkyl groups, in particular branched alkyl groups, having up to 10 C atoms, or that are substituted by oligoarylene groups, for example ortho-, meta-, para-, or branched terphenyl or quaterphenyl groups, are also suitable. If the compounds of formula (I) or the preferred embodiments are used as matrix material for a phosphorescent emitter or in a layer directly adjacent to a phosphorescent layer, it is further preferred if the compound does not contain any condensed aryl or heteroaryl groups in which more than two six-membered rings are directly condensed to one another.An exception to this are phenanthrene and triphenylene, which may be preferred due to their high triplet energy despite the presence of condensed aromatic six-membered rings.

[0106] In a preferred embodiment, the compounds according to the invention have a high degree of deuteration. It can preferably be provided that the degree of deuteration is at least 50%, preferably at least 80%, especially preferably at least 90%, and most preferably at least 95%. The degree of deuteration is determined from the numerical ratio of deuterium to the sum of deuterium and 1 H-hydrogen (D / (D+H)*100). The compounds are particularly preferably fully deuterated.

[0107] Preferably, compounds according to the invention, preferably compounds according to formulas (I), (II-1) to (II-26) and / or (III-1) to (III-6) have a molecular weight of less than or equal to 5000 g / mol, preferably less than or equal to 4000 g / mol, particularly preferably less than or equal to 3000 g / mol, especially preferably less than or equal to 2000 g / mol, more especially preferably less than or equal to 1200 g / mol and very particularly preferably less than or equal to 900 g / mol.

[0108] Furthermore, preferred compounds according to the invention are characterized by their sublimability. These compounds generally have a molecular weight of less than approximately 1200 g / mol.

[0109] The above-mentioned preferred embodiments can be combined with one another as desired within the limitations defined in claim 1. In a particularly preferred embodiment of the invention, the above-mentioned preferences occur simultaneously. Examples of preferred compounds according to the above-mentioned embodiments are the compounds listed in the following table.

[0110]

[0111] 

[0112] The basic structure of the compounds according to the invention can be prepared according to the methods outlined in the following schemes. The individual synthesis steps, such as coupling reactions leading to CC and / or CN bond formations, are known in principle to the person skilled in the art. These include, inter alia, reactions according to BUCHWALD, SUZUKI, YAMAMOTO, STILLE, HECK, NEGISHI, SONOGASHIRA, and HIYAMA. Further information on the synthesis of the compounds according to the invention

[0113] Compounds can be found in the synthesis examples.

[0114] The synthesis of the compounds according to the invention can be carried out, inter alia, according to the following Schemes 1, 2 and 3.

[0115] Scheme 1 describes the synthesis via the reaction of a benzil compound with a dibenzylideneacetone compound. Scheme 2 describes the cyclotrimerization of alkynes, and Scheme 3 describes the reaction of a halogen compound with a cyanide.

[0116] The benzil (1) and the dibenzylideneacetone (2) can be reacted under base catalysis, e.g. with an alkali metal alkoxide in an alcohol, in a Knoevenagel condensation to give the tetraarylcyclopentadienone (3), see e.g. JR Johnson, Organic Syntheses 1943, 23, 92. In a second step, (3) is reacted with an alkyne (4) in a high-boiling, inert solvent, preferably benzophenone or diphenyl ether, at elevated temperature, preferably > 200 °C, in a cascade of a Diel-Alder reaction followed by a retro-cheleotropic carbon monoxide elimination to give the compounds (5) according to the invention, see e.g. Louis F. Fieser, Organic Syntheses, 1966, 46, 44 or UC Kassehin et al., American Journal of Organic Chemistry, 2017, 7(1). 1.

[0117] Scheme 1 :

[0118]

[0119] R a : H, D, alkyl, aryl, heteroaryl, CN, etc. with the proviso that at least one of the radicals R aa CN group is

[0120] Alternatively, the compounds (5) according to the invention can be prepared by transition metal-catalyzed cyclotrimerization of alkynes (6, 7, 8), see, for example, H. Pepermans et al., Bull. Soc. Chim. 1988, 97 (2), 115, C. Müller, Organometallics 2002, 21, 1975, KP Angermund et al., Chem. Ber. 1993, 126, 713, JF Eisch et al., Organometallics 2000, 19, 1211 , Y.-l. Wang et al., Tetrahedron 73 (2017) 7210. If identical alkynes are used, uniform, symmetrical compounds (5) can be obtained; if different alkynes are used, different isomeric compounds (5) can be obtained in one step, whereby the resulting mixtures of substances can be separated, for example, chromatographically.

[0121] R a : H, D, alkyl, aryl, heteroaryl, CN, etc. with the proviso that at least one of the radicals R a a CN group is

[0122] Alternatively, the compounds (5) according to the invention can be prepared by halogen-cyano exchange, e.g. with CuCN or Zn(CN)2, optionally in the presence of a Pd catalyst, in a dipolar aprotic solvent such as DMF, DMAc, NMP, DMSO, etc., from halogenated hexaarylbenzenes (9), which are accessible by the above-mentioned methods.

[0123] The meaning of the symbols used in the scheme presented above corresponds essentially to that defined for formula (I), whereby, for reasons of clarity, numbering and a complete representation of all symbols, in particular the radicals R, R b and R c was omitted. A further subject of the present invention is therefore a process for preparing a compound according to the invention, wherein a diphenylalkyne compound is synthesized and reacted in a cyclomerization reaction.

[0124] By these processes, optionally followed by purification, such as recrystallization or sublimation, the compounds according to the invention can be obtained in high purity, preferably more than 99% (determined by 1 H-NMR and / or HPLC).

[0125] The compounds of the invention can also be mixed with a polymer. It is also possible to covalently incorporate these compounds into a polymer. This is particularly possible with compounds substituted by reactive leaving groups, such as bromine, iodine, chlorine, boronic acid, or boronic acid esters, or by reactive, polymerizable groups, such as olefins or oxetanes. These can be used as monomers to produce corresponding oligomers, dendrimers, or polymers. The oligomerization or polymerization preferably takes place via the halogen functionality or the boronic acid functionality, or via the polymerizable group, respectively. It is also possible to crosslink the polymers via such groups. The compounds and polymers of the invention can be used as crosslinked or uncrosslinked layers.

[0126] The invention therefore further provides oligomers, polymers or dendrimers comprising one or more of the above-listed compounds of the formula (I) and preferred embodiments of these compounds, wherein one or more bonds of the compounds of the formula (I) and preferred embodiments of this formula to the polymer, oligomer or dendrimer are present. Depending on the linkage of the structures of the formula (I) and preferred embodiments of this formula or of the compounds, these therefore form a side chain of the oligomer or polymer or are linked in the main chain. The polymers, oligomers or dendrimers can be conjugated, partially conjugated or non-conjugated. The oligomers or polymers can be linear, branched or dendritic. The same preferences apply to the repeating units of the compounds according to the invention in oligomers, dendrimers and polymers as described above.

[0127] To prepare the oligomers or polymers, the monomers according to the invention are homopolymerized or copolymerized with other monomers. Copolymers are preferred, wherein the units according to formula (I) or the preferred embodiments described above and below are present in amounts of 0.01 to 99.9 mol%, preferably 5 to 90 mol%, particularly preferably 20 to 80 mol%. Suitable and preferred comonomers which form the polymer backbone are selected from fluorenes (e.g. according to EP 842208 or WO 2000 / 022026), spirobifluorenes (e.g. according to EP 707020, EP 894107 or WO 2006 / 061181), para-phenylenes (e.g. according to WO 92 / 18552), carbazoles (e.g. according to WO 2004 / 070772 or WO 2004 / 113468), thiophenes (e.g. according to EP 1028136), dihydrophenanthrenes (e.g. according to WO 2005 / 014689), cis- and trans-indenofluorenes (e.g. according to WO 2004 / 041901 or WO 2004 / 113412), ketones (e.g. according to WO 2005 / 040302), phenanthrenes (e.g.according to WO 2005 / 104264 or WO 2007 / 017066) or several of these units. The polymers, oligomers, and dendrimers may contain further units, for example hole-transport units, in particular those based on triarylamines, and / or electron-transport units.

[0128] Of particular interest are also compounds according to the invention that are characterized by a high glass transition temperature. In this context, compounds according to the invention that have a glass transition temperature of at least 70 °C, more preferably of at least 110 °C, most preferably of at least 125 °C, and especially preferably of at least 150 °C, determined according to DIN 51005 (version 2005-08), are particularly preferred.

[0129] For processing the compounds of the invention from the liquid phase, for example by spin coating or printing processes, formulations of the compounds of the invention are required. These formulations can be, for example, solutions, dispersions, or emulsions. It may be preferred to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, a-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, Decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene,Phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butylmethyl ether, triethylene glycol butylmethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyl octanoate, heptylbenzene, menthyl isovalerate, cyclohexylhexanoate or mixtures of these solvents.

[0130] The present invention therefore further provides a formulation or a composition comprising at least one compound according to the invention and at least one further compound. The further compound can, for example, be a solvent, in particular one of the abovementioned solvents or a mixture of these solvents. If the further compound comprises a solvent, this mixture is referred to herein as a formulation. However, the further compound can also be at least one further organic or inorganic compound that is also used in the electronic device, for example an emitting compound and / or another matrix material.Preferably, it can be provided that at least one further compound is selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials, preferably host materials.

[0131] The present invention further relates to the use of a compound according to the invention in an electronic device, in particular in an organic electroluminescent device. Preferably, the compounds according to the invention can be used in an electronic device as a host material, electron transport material, electron injection material, or hole blocking material.

[0132] The present invention further relates to an electronic device comprising at least one compound according to the invention. An electronic device within the meaning of the present invention is a device that contains at least one layer containing at least one organic compound. The component may also contain inorganic materials or layers composed entirely of inorganic materials.

[0133] Particularly preferably, the electronic device is selected from the group consisting of organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), “organic plasmon emitting devices” (DM Koller et al., Nature Photonics 2008, 1- 4); organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs) and organic electrical sensors, preferably organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), particularly preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), in particular phosphorescent OLEDs.

[0134] The organic electroluminescent device contains a cathode, an anode, and at least one emitting layer. In addition to these layers, it may contain further layers, for example, one or more hole-injection layers, hole-transport layers, hole-blocking layers, electron-transport layers, electron-injection layers, exciton-blocking layers, electron-blocking layers, and / or charge-generation layers. Interlayers, which, for example, have an exciton-blocking function, may also be inserted between two emitting layers. It should be noted, however, that not all of these layers are necessarily present. The organic electroluminescent device may contain one emitting layer or it may contain multiple emitting layers.If multiple emission layers are present, they preferably have a total of multiple emission maxima between 380 nm and 750 nm, resulting in overall white emission. This means that different emitting compounds that can fluoresce or phosphoresce are used in the emitting layers. Systems with three emitting layers are particularly preferred, with the three layers exhibiting blue, green, and orange or red emission. The organic electroluminescent device according to the invention can also be a tandem electroluminescent device, particularly for white-emitting OLEDs.

[0135] The compound according to the invention can be used in different layers, depending on the precise structure. Preference is given to an organic electroluminescent device comprising a compound according to formula (I) or the preferred embodiments described above in an emitting layer as a matrix material for phosphorescent emitters or for emitters that exhibit TADF (thermally activated delayed fluorescence), in particular for phosphorescent emitters. Furthermore, the compound according to the invention can also be used in an electron-transport layer and / or in a hole-blocking layer. The compound according to the invention is particularly preferably used as a matrix material for phosphorescent emitters, in particular for red, orange, blue, green, or yellow, preferably for blue or green phosphorescent emitters, in an emitting layer, as a host material, electron-transport material, electron-injection material, or hole-blocking material.

[0136] Preferably, it can be provided that the organic electroluminescent device comprises at least one emission layer and at least one electron transport layer and the electron transport layer contains the compound according to the present invention.

[0137] When the compound according to the invention is used as a matrix material for a phosphorescent compound in an emitting layer, it is preferably used in combination with one or more phosphorescent materials (triplet emitters). Phosphorescence, within the meaning of this invention, refers to luminescence from an excited state with higher spin multiplicity, i.e., a spin state > 1, in particular from an excited triplet state. For the purposes of this application, all luminescent complexes with transition metals or lanthanides, in particular all iridium, platinum, and copper complexes, are to be considered phosphorescent compounds.

[0138] The mixture of the compound according to the invention and the emitting compound contains between 99 and 1 vol. %, preferably between 98 and 10 vol. %, particularly preferably between 97 and 60 vol. %, in particular between 95 and 80 vol. % of the compound according to the invention, based on the total mixture of emitter and matrix material. Accordingly, the mixture contains between 1 and 99 vol. %, preferably between 2 and 90 vol. %, particularly preferably between 3 and 40 vol. %, in particular between 5 and 20 vol. % of the emitter, based on the total mixture of emitter and matrix material. In one embodiment of the invention, the compound according to the invention is used as the sole matrix material (“single host”) for the phosphorescent emitter.

[0139] A further embodiment of the present invention is the use of the compound according to the invention as a matrix material for a phosphorescent emitter in combination with another matrix material. Suitable matrix materials that can be used in combination with the compounds according to the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, e.g., according to WO 2004 / 013080, WO 2004 / 093207, WO 2006 / 005627, or WO 2010 / 006680, triarylamines, carbazole derivatives, e.g., B. CBP (N,N-biscarbazolylbiphenyl) or those in WO 2005 / 039246, US 2005 / 0069729, JP 2004 / 288381, EP 1205527, WO 2008 / 086851 or WO 2013 / 041176, indolocarbazole derivatives, e.g. according to WO 2007 / 063754 or WO 2008 / 056746, indenocarbazole derivatives, e.g. according to WO 2010 / 136109, WO 2011 / 000455, WO 2013 / 041176 or WO 2013 / 056776, azacarbazole derivatives, e.g. B. according to EP 1617710, EP 1617711 , EP 1731584, JP 2005 / 347160, bipolar matrix materials, e.g.according to WO 2007 / 137725, silanes, e.g. according to WO 2005 / 111172, azaboroles or boronate esters, e.g. according to WO 2006 / 117052, triazine derivatives, e.g. according to WO 2007 / 063754, WO 2008 / 056746, WO 2010 / 015306, WO 2011 / 057706, WO 2011 / 060859 or WO 2011 / 060877, zinc complexes, e.g. according to EP 652273 or WO 2009 / 062578, diazasilole or tetraazasilole derivatives, e.g. according to WO 2010 / 054729, diazaphosphole derivatives, e.g. B. according to WO 2010 / 054730, bridged carbazole derivatives, e.g. according to WO 2011 / 042107, WO 2011 / 060867, WO 2011 / 088877 and WO 2012 / 143080, triphenylene derivatives, e.g. according to WO 2012 / 048781, dibenzofuran derivatives, e.g. according to WO 2015 / 169412, WO 2016 / 015810, WO 2016 / 023608, WO 2017 / 148564 or WO 2017 / 148565 or biscarbazoles, e.g. according to JP 3139321 B2.

[0140] Here, the concentration of a compound according to formula (I), as described above or preferably described, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is usually in the range from 10 wt.% to 95 wt.%, preferably in the range from 15 wt.% to 90 wt.%, more preferably in the range from 15 wt.% to 80 wt.%, even more preferably in the range from 20 wt.% to 70 wt.%, very particularly preferably in the range from 40 wt.% to 80 wt.% and most preferably in the range from 50 wt.% to 70 wt.%, based on the total mixture or based on the total composition of the light-emitting layer.

[0141] Likewise, another phosphorescent emitter, which emits at a shorter wavelength than the actual emitter, can be present in the mixture as a co-host. Particularly good results are achieved when a red-phosphorescent emitter is used as the emitter and a yellow-phosphorescent emitter is used as the co-host in combination with the compound according to the invention.

[0142] Furthermore, a compound can be used as co-host which does not participate, or does not participate to a significant extent, in charge transport, as described, for example, in WO 2010 / 108579. Particularly suitable co-matrix material in combination with the compound according to the invention are compounds which have a large band gap and which themselves do not participate, or at least do not participate to a significant extent, in the charge transport of the emitting layer. Such materials are preferably pure hydrocarbons. Examples of such materials can be found, for example, in WO 2009 / 124627 or WO 2010 / 006680. In this context, it should be noted that compounds according to the invention without special functional groups, for example hole transport groups and / or electron transport groups, have advantageous properties.

[0143] Particularly suitable phosphorescent compounds (= triplet emitters) are compounds that emit light upon suitable excitation, preferably in the visible range, and also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, in particular a metal with this atomic number. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, indium, palladium, platinum, silver, gold, or europium are preferably used as phosphorescent emitters, in particular compounds containing indium or platinum.

[0144] The term phosphorescent emitters typically encompasses compounds in which light emission occurs through a spin-forbidden transition from an excited state with higher spin multiplicity, i.e., a spin state > 1, for example, through a transition from a triplet state or a state with an even higher spin quantum number, for example, a quintet state. Preferably, this refers to a transition from a triplet state. Generally, all phosphorescent complexes as used in the prior art for phosphorescent OLEDs and as known to those skilled in the art in the field of organic electroluminescent devices are suitable. Preferred examples of phosphorescent emitters are described in WO2019 / 007867 on pages 120 to 126 in Table 5 and on pages 127 to 129 in Table 6. The emitters are incorporated into the description by this reference.

[0145] Examples of phosphorescent dopants are listed in the following table.

[0146]

[0147] 

[0148] The compounds of the invention are also particularly suitable as matrix materials for phosphorescent emitters in organic electroluminescent devices, as described, for example, in WO 98 / 24271, US 2011 / 0248247, and US 2012 / 0223633. In these multicolor display components, an additional blue emission layer is vapor-deposited over the entire surface of all pixels, even those with a color other than blue.

[0149] In a further embodiment of the invention, the organic electroluminescent device according to the invention does not contain a separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, i.e. the emitting layer directly adjoins the hole injection layer or the anode, and / or the emitting layer directly adjoins the electron transport layer or the electron injection layer or the cathode, as described, for example, in WO 2005 / 053051. Furthermore, it is possible to use a metal complex that is the same as or similar to the metal complex in the emitting layer directly adjacent to the emitting layer as a hole transport or hole injection material, as described, for example, in WO 2009 / 030981.

[0150] In the further layers of the organic electroluminescent device according to the invention, all materials can be used as they are commonly used according to the prior art. Therefore, the person skilled in the art can, without inventive step, use all materials known for organic electroluminescent devices in combination with the compounds according to the invention according to formula (I) or the preferred embodiments described above. Also preferred is an organic electroluminescent device characterized in that one or more layers are coated using a sublimation process. The materials are coated in vacuum sublimation systems at an initial pressure of less than 10' 5 mbar, preferably less than 10' 6 mbar. However, it is also possible that the initial pressure is even lower, for example less than 10' 7 mbar.

[0151] Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using the OVPD (Organic Vapor Phase Deposition) process or by means of carrier gas sublimation. The materials are sublimated at a pressure between 10' 5 mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured.

[0152] Also preferred is an organic electroluminescent device characterized in that one or more layers are produced from solution, such as by spin coating, or by any printing process, such as screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), inkjet printing, or nozzle printing. Soluble compounds are required for this, which are obtained, for example, by suitable substitution.

[0153] Formulations for applying a compound according to formula (I) or the preferred embodiments thereof presented above are novel. The present invention therefore further provides formulations comprising at least one solvent and a compound according to formula (I) or the preferred embodiments thereof presented above. Furthermore, hybrid processes are possible, in which, for example, one or more layers are applied from solution and one or more further layers are vapor-deposited.

[0154] These processes are generally known to the person skilled in the art and can be applied by him without inventive step to organic electroluminescent devices containing the compounds according to the invention.

[0155] The compounds of the invention and the organic electroluminescent devices of the invention are distinguished from the prior art, in particular by improved efficiency or operating voltage. The other electronic properties of the electroluminescent devices, such as lifetime, remain at least as good. In a further variant, the compounds of the invention and the organic electroluminescent devices of the invention are distinguished from the prior art, in particular by improved efficiency and / or operating voltage and a longer lifetime. Furthermore, these compounds and the organic electroluminescent devices obtainable therefrom exhibit a low refractive index (RI).

[0156] The electronic devices according to the invention, in particular organic electroluminescent devices, are characterized by one or more of the following surprising advantages over the prior art:

[0157] 1 . Electronic devices, in particular organic electroluminescent devices comprising compounds according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, have excellent efficiency. In this case, compounds according to the invention according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, have a low operating voltage when used in electronic devices. Electronic devices, in particular organic electroluminescent devices comprising compounds according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, have a very good lifetime. In this case, these compounds in particular cause a low roll-off, iea slight drop in the power efficiency of the device at high luminance levels. The compounds of the formula (I) according to the invention and the preferred embodiments set out above and below display very high stability. Electronic devices, in particular organic electroluminescent devices comprising compounds of the formula (I) and the preferred embodiments set out above and below, in particular as matrix material or as electron-conducting materials, have very low refractive indices. Using compounds of the formula (I) and the preferred embodiments set out above and below, the formation of optical loss channels can be avoided in electronic devices, in particular organic electroluminescent devices. As a result, these devices are characterized by high PL and thus high EL efficiency of emitters andexcellent energy transfer from the matrices to dopants. Compounds according to formula (I) and the preferred embodiments described above and below exhibit excellent glass film formation. These aforementioned advantages are not accompanied by an excessive deterioration of the other electronic properties.

[0158] It should be noted that variations of the embodiments described in the present invention fall within the scope of this invention. Any feature disclosed in the present invention may, unless explicitly excluded, be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless otherwise stated, any feature disclosed in the present invention is to be considered an example of a generic series or an equivalent or similar feature.

[0159] All features of the present invention may be combined with each other in any way, unless certain features and / or steps are mutually exclusive. This applies in particular to preferred features of the present invention. Likewise, features of non-essential combinations may be used separately (and not in combination).

[0160] It should further be noted that many of the features, and particularly those of the preferred embodiments of the present invention, are inventive in their own right and should not be considered merely part of the embodiments of the present invention. Independent protection may be sought for these features in addition to or alternatively to any presently claimed invention.

[0161] The teaching of technical action disclosed in the present invention can be abstracted and combined with other examples.

[0162] The invention is further illustrated by the following examples, without intending to limit it. Those skilled in the art can, from the descriptions, practice the invention within the entire disclosed scope and, without inventive step, prepare further compounds according to the invention and use them in electronic devices or apply the inventive method. Examples:

[0163] Unless otherwise stated, the following syntheses were carried out under a protective gas atmosphere in dried solvents. Solvents and reagents can be purchased from Sigma-Aldrich or ABCR, for example. The respective information in square brackets or the numbers given for individual compounds refer to the CAS numbers of the known compounds. For compounds that can exhibit multiple enantiomeric, diastereomeric, rotameric, or tautomeric forms, one form is shown as a representative example.

[0164] B) Synthesis of synthons S:

[0165] Example S1 :

[0166] Preparation analogous to JR Johnson, Organic Syntheses 1943, 23, 92.

[0167] Batch: 26.0 g (100 mmol) LS2 and 21.0 g (100 mmol) LS50.

[0168] Yield: 23.5 g (54 mmol) %; Purity: approx. 97 % 1 H-NMR. The following compounds can be prepared analogously.

[0169] C) Synthesis of the compounds B according to the invention:

[0170] Example B1:

[0171] Representation analogous to Louis F. Fieser, Organic Syntheses, 1966, 46, 44 or UC Kassehin et al., American Journal of Organic Chemistry, 2017, 7(1 ), 1.

[0172] Batch: 24.4 g (120 mmol) LS200 and 38.5 g (100 mmol) LS500. The crude product was purified by chromatography (Torrent column system from A. Semrau) and / or repeated hot extraction crystallization (common organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) as well as fractional sublimation or annealing under high vacuum. Yield: 43.7 g (78 mmol) 78%; Purity: approximately 99.9% by HPLC. become.

[0173] Example: Production of OLEDs

[0174] The production of OLEDs according to the invention as well as OLEDs according to the prior art is carried out according to a general process according to WO 2004 / 058911 , which is adapted to the conditions described here (layer thickness variation, materials used).

[0175] The following examples present the results of various OLEDs. Cleaned glass plates (cleaned in a Miele laboratory dishwasher, using Merck Extran cleaner) coated with 50 nm thick structured ITO (indium tin oxide) are pretreated with UV ozone for 25 minutes (UV ozone generator PR-100, UVP). These coated glass plates form the substrates onto which the OLEDs are applied. a) Blue fluorescent OLED devices - BF:

[0176] The compounds B according to the invention can be used in the hole-blocking layer (HBL) and the electron-transport layer (ETL). All materials are thermally vapor-deposited in a vacuum chamber. The emission layer (EML) always consists of at least one matrix material (host material) SMB (see Table 1) and an emitting dopant (dopant, emitter) D, which is admixed to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as SMB:D (97%:3%) means that the SMB material is present in the layer in a volume fraction of 97% and the dopant D in a volume fraction of 3%. Analogously, the electron-transport layer can also consist of a mixture of two materials, see Table 1. The materials used to produce the OLEDs are shown in Table 5 or refer to the previously presented synthesis examples.

[0177] OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd / A), power efficiency (measured in λ / W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd / m². 2

[0178] The OLEDs have the following layer structure:

[0179] Substrat

[0180] Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm

[0181] Hole transport layer (HTL), made of HTM1, 180 nm

[0182] Electron blocking layer (EBL), see Table 1

[0183] Emission layer (EML), see Table 1

[0184] Hole blocking layer (HBL), see Table 1

[0185] Electron transport layer (ETL), see Table 1

[0186] Electron injection layer (EIL) made of ETM2, 1 nm

[0187] Cathode made of aluminum, 100 nm

[0188] Table 2: Results of blue fluorescent OLED devices b) Phosphorescent OLED components:

[0189] The compounds B according to the invention can be used in the hole-blocking layer (HBL), the electron-transport layer (ETL), and in the emission layer (EML) as electron-conducting matrix material (host material) (eTMM). For this purpose, all materials are thermally vapor-deposited in a vacuum chamber. The emission layer always consists of at least one or more matrix materials M and a phosphorescent dopant Ir, which is admixed to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as M1:M2:Ir (55%:35%:10%) means that the material M1 is present in the layer in a volume fraction of 55%, M2 in a volume fraction of 35%, and Ir in a volume fraction of 10%. Analogously, the electron-transport layer can also consist of a mixture of two materials. The exact structure of the OLEDs can be found in Table 3.The materials used to fabricate the OLEDs are shown in Table 5 or refer to the synthesis examples presented previously.

[0190] OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd / A), power efficiency (measured in λ / W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd / m². 2

[0191] The OLEDs have the following layer structure:

[0192] Substrat

[0193] Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm

[0194] Hole transport layer (HTL) made of HTM1, 180 nm for blue, 50 nm for green, yellow and red

[0195] Electron blocking layer (EBL), see Table 3

[0196] Emission layer (EML), see Table 3

[0197] Hole blocking layer (HBL), see Table 3

[0198] Electron transport layer (ETL), see Table 3

[0199] Electron injection layer (EIL) made of ETM2, 1 nm

[0200] Cathode made of aluminum, 100 nm

[0201] Table 3: Structure of phosphorescent OLED components

[0202] Table 4: Results of phosphorescent OLED devices

[0203] Table 5: Structural formulas of the materials used

Claims

Patent claims 1. Compound according to formula (I), where the symbols are: R, R a , R b , R c is, at each occurrence, the same or different: H, D, OH, F, CI, Br, I, CN, NO2, N(Ar')2, N(R 1 )2, C(=O)N(Ar')2, C(=O)N(R 1 )2, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, B(Ar')2, B(R 1 )2, C(=O)Ar', C(=O)R 1 , P(=O)(Ar')2, P(=O)(R 1 )2, P(Ar')2, P(R 1 )2, S(=O)Ar', S(=O)R 1 , S(=O)2Ar', S(=O)2R 1 , OSO2Ar', OSO2R 1 , a straight-chain alkyl group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group is each substituted by one or more radicals R 1may be substituted, where one or more non-adjacent CH2 groups are substituted by , C=Se, C=NR O or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 1 can be substituted, two radicals R, R a , R b , R c also form a ring system with each other; Ar' is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted, whereby two radicals Ar' which bind to the same C atom, Si atom, Ge atom, N atom, P atom or B atom may also be connected by a single bond or a bridge selected from B(R 1 ), C(R 1 )2, Si(R 1 )2, Ge(R 1 )2, C=O, C=NR 1 , C=C(R 1)2, 0, S, S=O, SO2, N(R 1 ), P(R 1 ) and P(=O)R 1 , be bridged together; R 1 is, at each occurrence, the same or different: H, D, F, CI, Br, I, CN, NO2, N(Ar”)2, N(R 2 )2, C(=O)Ar”, C(=O)R 2 , P(=O)(Ar”)2, P(Ar”)2, B(Ar”)2, B(R 2 )2, C(Ar”)3, C(R 2 )3, Si(Ar”)3, Si(R 2 )3, Ge(Ar”)3, Ge(R 2 )3, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R 2 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 2 C=CR 2 -, -C=C-, Si(R 2 )2, Ge(R 2 )2, C=O, C=S, C=Se, C=NR 2 , -C(=O)O-, -C(=O)NR 2 - NR 2 , P(=O)(R 2), SO or SO2 and wherein one or more H atoms may be replaced by D, F, CI, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 2 can be substituted, two or more radicals R 1 form a ring system, whereby one or more residues R 1 form a ring system with another part of the compound; Ar” is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is reacted with one or more residues R 2 may be substituted, in which case two radicals Ar” which bind to the same C-atom, Si-atom, Ge-atom, N-atom, P-atom or B-atom may also be bonded by a single bond or a bridge selected from B(R 2 ), C(R 2 )2, Si(R 2 )2, Ge(R 2)2, C=O, C=NR 2 , C=C(R 2 )2, 0, S, S=O, SO2, N(R 2 ), P(R 2 ) and P(=O)R 2 , be bridged together; R 2 is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CI, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more substituents R 2 form a ring system with each other; and i is 0, 1 or 2.

2. A compound according to claim 1, characterized in that at least one of the radicals R a , R b , R c stands for CN.

3. A compound according to claim 1 or 2, characterized in that the sum of the indices i is at most 8.

4. A compound according to one or more of claims 1 to 3, characterized in that at most 8 of the radicals R a , R b , R c are not equal to H or D.

5. A compound according to any one of formulas (II-1) to (II-26), Formula (11-11) Formula (11-12) 35 Formula (11-25) Formula (11-26) where the symbols i, R, R a , R b and R c have the meanings given in claim 1.

6. A compound according to claim 5, characterized in that at most one of the radicals R a , R b , R c stands for CN.

7. A compound according to claim 5 or 6, characterized in that at most 10 of the radicals R a , Rb , R c are not equal to H or D.

8. A compound according to one or more of claims 1 to 7, characterized in that at most one of the radicals R is CN.

9. A compound according to one or more of claims 1 to 8, characterized in that at most two of the radicals R, R a , R b , R c in a phenyl ring represents CN.

10. A compound according to one or more of claims 1 to 9, characterized in that at least one radical R, R a , R b , R c is selected, identically or differently at each occurrence, from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, Quinoxaline, phenanthrene or triphenylene, each of which is substituted with one or more residues R 1 can be substituted 11. A compound according to one or more of claims 1 to 10, wherein at least two, preferably adjacent, radicals R, R a , R b , R c with the other groups to which the two residues R, R a , R b , R c bind, forming a condensed ring, where the radicals R, R a , R b , R c Form structures of the formula (RB), Formula RB where R 1 has the meaning set out in claim 1, the dashed bonds represent the attachment points via which the two radicals R, R a , R b , R c bind, the index m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and Y 2 C(R 1 )2, NR 1 , NAr', BR 1 , BAr', 0 or S, preferably C(R 1)2, NAr' or 0, particularly preferably C(R 1 )2or O.

12. A compound according to one or more of claims 1 to 11, selected from the compounds of formulas (III-1) to (III-6), wherein the compounds have at least one condensed ring Formula (111-1 ) Formula (III-2) Formula (III-5) Formula (III-6) where the symbols R, R a , R b and R c have the meanings given in claim 1, the symbol o stands for the condensation sites of the at least one condensed ring and the following applies to the further indices used: k is independently 0 or 1 at each occurrence; and i is independently 0, 1 or 2 at each occurrence, preferably 0 or 1.

13. Formulation comprising at least one compound according to one or more of claims 1 to 12 and at least one further compound, wherein the further compound is preferably selected from one or more solvents.

14. Composition comprising at least one compound according to one or more of claims 1 to 12 and at least one further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials, preferably host materials.

15. Use of a compound according to one or more of claims 1 to 12 in an electronic device, preferably as host material, electron injection material, electron transport material or hole blocking material.

16. Electronic device comprising at least one compound according to one or more of claims 1 to 12.

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